Improvement in stretchers for stereotype-matrices



T. l. MAYALL & R. W. HARTNETT.

Stretch er for Stereatype-Matrices. N0.\59,696 Patented Feb.9,\875.

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W a I mrrnn STATES FFIC E PATENT THOMAS J. MAYALL AND RICHARD W. HARTNETT, OF BOSTON MASSAOHU- SETTS, ASSIGNORS TO MAYALL POWER PRINTING-PRESS COMPANY, .OF

NEW YORK CITY.

Specification forming part of Letters Patent No. 159,696, dated February 9, 1875 application filed N vember 23, 1874.

To all whom it may concern Be it known that we, THoMAs J. MAYALL and RICHARD W. HARTNETT, both of Boston, Sufiolk county, Massachusetts, have invented certain new and useful Improvements in Stretchers for Matrices of Stereotype-Plates, of which the following is a specification:

Our invention relates to means for holding down flat the paper matrix of a stereotypeplate during the drying of the same.

The device for this purpose-termed a stretcherwe make of a rectangular open or skeleton frame, of such size that its margins will coincide with the margin or flat unraised outer boundary of the matrix. The area or space inclosed by the metallic margin we fill with a sheet of wire-gauze, which is firmly united to the frame, but is set back in rear of the face of the margin of the frame a distance equal to the thickness of the matrix, so that the wire-gauze or netting part of the frame in reality constitutes a recess, iii which the raised or type-impressed part of the matrix can be confined or held without injuriously pressing on said part. The wire net or gauze which thus holds the type-impressed part of the matrix allows the heat free access to, and direct contact with, the matrix.

In the accompanying drawing we have indicated the manner inwhich we prefer to carry our invention into effect.

Figure l is a perspective view of a stretcher opened. Fig. 2 is a like view of the same closed.

A is a metallic skeleton or open frame, whose margin a corresponds in dimensions and contour with the margin of the matrix, (formed by the chase of the type-form.) Within this-margin is secured a sheet of wire netting or gauze, b, which, in case but one frame A is used, is set back from or in rear of the face of the margin to a distance equal to the thickness of the type-impressed portion of the matrix. In case two frames, hinged together, as indicated in the drawing, are used, then the wire-gauze in each frame need be set back in rear of the margin but half the distance required in a single frame; the object being to provide a recess in which the type-impressed part of the matrix may be received and protected from the pressure to'which it would otherwise be subjected When held between the two surfaces, which are applied to it during the drying operation.

As before mentioned, we prefer to use a double-frame stretcher, the two frames being hinged at c, and being clamped together, when closed on the matrix, by means of a clampbolt and nut, cl, hinged to one of the frames. The shank of the bolt enters a vertical slot in the edge of the other frame, and when it is thus placed the nut is screwed down, so as to bind the two frames tightly together. The margin of the matrix is thus caught and held between the contiguous margins at of the frames, and the type-impressed parts of the matrix are confined between the two wiregauze or open-work faces I), which keep the matrix flat and even without inj uriously pressing it. The margin a, by holding onto the margin of the matrix, keeps the latter stretched, and prevents undue shrinkage or expansion. The wire-gauze face also admits heat to direct contact with the matrix from above and below, which is very necessary where the stretcher, with inclosed matrix, is placed in a steamheated oven, as we propose to do.

In case it is proposed to use but a single frame, the recess in this frame extends partly into the margins a, so that it may be of sufficient extent to receive all of the matrix, including the margin. The wire-gauze netting is set back in rear of the plane of this recess in the margin a sufficient distance, as before provided, to accommodate the increased thickness of the raised or type-impressed portion of the matrix. The single-frame stretcher is put down over the matrix, and can then be pushed along, carrying the matrix with it, on the steam-table or into the oven.

What we claim, and desire to secure by Letters Patent, is-

1. In stretchers for the matrices of stereotype-plates, the combination of a metallic skeleton frame or margin, which registers with the unimpressed margin of the matrix, and a wiregauze or net sheet, which is set back from the plane of said frame or margin a distance to correspond with the increased thickness of the said frames being hinged, and provided with a device for clamping them together when closed, as shown and set forth.

In testimony whereof we have hereunto signed our names this 23d day of November,

THOS. J. MAYALL. RIGHD. W. HARTNETT. Witnesses:

EWELL A. DICK, HENRY B. ELLIOTT. 

